Polyether block copolymers of the general structure B-(A-OH)n are described, where n is greater than or equal to 2 and blocks A are made up of polyoxypropylene units and the central block B of polyoxytetramethylene, polyoxyethylene, polybutadiene, polyisoprene, polyacrylate, polymethacrylate, polyamide, polyurethane, or polyester units. These polyether block copolymers are suitable for the manufacture of compositions that serve as the basis for preparations for use as a one-component moisture-hardening or two-component adhesive or sealant, for assembly bonding, for areal bonding, and/or for coating, as a reactive melt adhesive or as a laminating adhesive.